On May 30th of 2014 we lost a truly gifted and outstanding geochemist, pioneer, loyal friend, co-founder of the Association of Applied Geochemists (then the Association of Exploration Geochemists, AEG, and now AAG), and founder of the Association’s first journal, the Journal of Exploration Geochemistry (JGE): Eion M. Cameron.

Most of Eion’s long and illustrious career was spent at the Geological Survey of Canada (1966–2000) as both a research geochemist and as Head of the Applied Geochemistry Subdivision, comprising some 32 scientists and technical staff. A major emphasis of Eion’s research was on the development, testing and application of new and improved methods of detecting ore deposits both at surface and buried at depth. His accomplishments in this area are diverse. For example, he established lake sediment and water geochemistry as an effective mineral exploration tool in Canada’s north. In 1972, Eion carried out the first regional-scale geochemical survey in Canada, sampling lake sediments and waters over 93 000 km2 of the Northwest Territories in only six weeks with three choppers and one float plane. Some of the discoveries, as a result, are the Yava and Hackett River VMS deposits. This survey paved the way for Canada’s National Geochemical Reconnaissance Program. Still in the 1970s, he led the first GSC multi-disciplinary multi-agency project: Uranium Exploration in the Athabasca Basin.

Through his extensive research globally on the genesis of different deposit types, Eion developed new rock geochemical techniques for locating lode gold, porphyry copper and VMS/SEDEX base metal deposits. Eion’s intense interest in the source of metals in deposits took him to examine rocks far and deeper than the deposit levels. He went Norway to study granulites (lower crustal rocks) to evaluate such high temperature metamorphism could release gold to form deposits at shallow crustal levels and published a highly acclaimed paper in Geology. This illustrates his strong scientific curiosity and ability to link diverse information to make a coherent model. Other areas where Eion made major scientific advances are too numerous to mention here but he is highly acclaimed for his ground-breaking research on the Precambrian sulphur cycle and the timing of great oxygenation of Earth; the information is critical to our understanding of ocean and atmosphere evolution. This seminal research, published in journals such as Nature, is still cited extensively today and forms the basis of recent research on the sulphur cycle employing other isotopes, particularly 33S.

Eion was an absolutely outstanding scientist who won numerous awards and who, in 1970, co-founded the Association of Exploration Geochemists which later became the Association of Applied Geochemists and two years later started the Journal of Geochemical Exploration, the JGE (he was Editor-in-Chief for 25 years). For his scientific career achievements, and there are many, he won the AAG gold medal, and for his dedication to the Association and his influence on so many facets of it through the years, he won the silver medal and honorary lifetime membership. In later years he spent many hours a month carefully managing the AAG investments, who better than a market-savvy Scot for that task?!

The following is a quote from Eion’s speech when he received the AAG honorary membership:

“I have been most fortunate in my professional career. For 13 years I had administrative responsibility for applied geochemistry in the GSC at a time when the GSC as a whole was at its peak of influence and support. Following this I was a part-time prof for 16 years at the University of Ottawa in a department where academic politics was absent, because individual members of faculty genuinely liked each other. Most recently I have been involved with the mining industry as a consultant and as a researcher; roles that have been as rewarding as the best of my previous experiences. The common link between all these periods is my association as an active member of the AEG (now AAG). It is perhaps best to be part of a society of moderate size, because one can develop a camaraderie with all of the other active members. That is the best award of all.”

As just mentioned, Eion was an Adjunct Professor at Ottawa University (1983–2000); he enjoyed this enormously, mostly because of the collegial and stimulating environment in the Department of Earth Sciences. During the time, Eion actively engaged graduate teaching and mentoring by offering formal graduate courses, providing advices to students and supervising thesis projects. Among these 10 lucky graduate students directly supervised by Eion include Stephen Rowin (Director of BC Geological Survey), Saeed Alirezaei (Professor Shahid Beheshti University in Tehran), Bahram Daneshfar (Agriculture Canada, part-time Professor at the University of Ottawa). There he worked with and made a very good friend of Keiko Hattori, co-editor of this special issue.

One of the key factors that led to such success in Eion’s research is his early recognition that one needs to incorporate knowledge or technology from peripheral fields of study such as soil science, analytical chemistry, statistics, physics, oceanography, mineralogy and microbiology. Many people would stay in our own comfortable disciplines, but Eion was not afraid to venture into different disciplines. There are very few scientists who can or would have the foresight to delve into quite different fields to obtain this much more comprehensive view. Another of Eion’s talents, demonstrated so well in all the publications from his ‘Deep Penetrating Geochemistry’ (he coined this phrase) work, was his ability to analyse, unravel and describe, in fairly simple terms, processes of complex geochemical phenomena. His c. 200 publications are superb, in their clarity, organisation and brilliance. In the CAMIRO (Canadian Mining Industry Research Organisation) study that Eion led – where Stew Hamilton, Beth McClenaghan and I worked with him as a team – he produced about 30 individual reports that were unique in that they could be read and understood by the highly trained geochemist and the field-oriented prospector alike. He extracted the essence of each piece of the puzzle to complete it. He was great fun to be with in the field; his love for the science of geochemistry was so infectious and stimulating.

Regardless of these gifts, Eion was very modest; confident, yes, but modest. He never stopped learning; whether it was in science, business, financial investments, people, world affairs, cultural matters etc., his curiosity did not wane.